How to Calculate Normality of a Solution

How to Calculate Normality of a Solution The normality of a solution is the gram equivalent weight of a solute per liter of solution. It may also be called the equivalent concentration.  It is indicated using the symbol N, eq/L, or meq/L ( 0.001 N) for units of concentration. For example, the concentration of a hydrochloric acid solution might be expressed as 0.1 N HCl. A gram equivalent weight or equivalent is a measure of the reactive capacity of a given chemical species (ion, molecule, etc.). The equivalent value is determined using the molecular weight and valence of the chemical species. Normality is the only concentration unit that is reaction dependent. Here are examples of how to calculate the normality of a solution. Key Takeaways Normality is a unit of concentration of a chemical solution expressed as gram equivalent weight of solute per liter of solution. A defined equivalence factor must be used to express concentration.Common units of normality include N, eq/L, or meq/L.Normality is the only unit of chemical concentration that depends on the chemical reaction being studied.Normality is not the most common unit of concentration, nor is its use appropriate for all chemical solutions. Typical situations when you might use normality include acid-base chemistry, redox reactions, or precipitation reactions. For most other situations, molarity or molality are better options for units. Normality Example #1 The easiest way to find normality is from molarity. All you need to know are how many mole of ions dissociate. For example, a 1 M sulfuric acid (H2SO4) is 2 N for acid-base reactions because each mole of sulfuric acid provides 2 moles of H ions. 1 M sulfuric acid is 1 N for sulfate precipitation since 1 mole of sulfuric acid provides 1 mole of sulfate ions. Normality Example #2 36.5 grams of hydrochloric acid (HCl) is a 1 N (one normal) solution of HCl. A normal is one gram equivalent of a solute per liter of solution. Since hydrochloric acid is a strong acid that dissociates completely in water, a 1 N solution of HCl would also be 1 N for H or Cl- ions for acid-base reactions. Normality Example #3 Find the normality of 0.321 g sodium carbonate in a 250 mL solution. To solve this problem, you need to know the formula for sodium carbonate. Once you realize there are two sodium ions per carbonate ion, the problem is simple: N 0.321 g Na2CO3  x (1 mol/105.99 g) x (2 eq/1 mol)N 0.1886 eq/0.2500 LN 0.0755 N Normality Example #4 Find the percent acid (eq wt 173.8) if 20.07 mL of 0.1100 N base is required to neutralize 0.721 g of a sample. This is essentially a matter of being able to cancel out units to obtain the final result. Remember, if given a value in milliliters (mL), its necessary to convert it to liters (L). The only tricky concept is realizing the acid and base equivalence factors will be in a 1:1 ratio. 20.07 mL x (1 L/1000 mL) x (0.1100 eq base/1 L) x (1 eq acid/1 eq base) x (173.8 g/1 eq) 0.3837 g acid When to Use Normality There are specific circumstances when its preferable to use normality rather than molarity or other unit of concentration of a chemical solution. Normality is used in acid-base chemistry to describe the concentration of hydronium (H3O) and hydroxide (OH-). In this situation, 1/feq is an integer.The equivalence factor or normality is used in precipitation reactions to indicate the number of ions that will precipitate. Here, 1/feq is once again and integer value.In redox reactions, the equivalence factor indicates how many electrons can be donated or accepted by an oxidizing or reducing agent. For redox reactions, 1/feq may be a fraction. Considerations Using Normality Normality is not an appropriate unit of concentration in all situations. First, it requires a defined equivalence factor. Second, the normality is not a set value for a chemical solution. Its value can change according to the chemical reaction being examined. For example, a solution of CaCl2 that is 2 N with respect to the chloride (Cl-) ion would only be 1 N with respect to the magnesium (Mg2) ion. Reference The use of the equivalence concept. IUPAC (archived).

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Online Public Schools for Wisconsin Students Wisconsin offers resident students the opportunity to take online public school courses for free. Though students normally attend a public school in the district where they live, Wisconsin allows students to enroll in public schools in other districts, so although a school is chartered in one district, students statewide can enroll.    JEDI Virtual Online PK-12 School JEDI Virtual School, a not-for-profit charter school, offered its first distance education class in the 1996-1997 school year and was the first school of its kind in Wisconsin.   JEDI focuses on personalized attention. Full-time online students are assigned, in addition to their highly qualified teachers, learning coaches to help with time management and tracking students’ achievements. Also, a student services coordinator oversees course schedules, monitors grades and attendance, and makes any necessary schedule adjustments. Curriculum options include AP and dual-credit courses. The chartering district is  Whitewater Unified School District.   Wisconsin Virtual Academy Wisconsin Virtual Academy (WIVA)’s core values are â€Å"Achieve, Communicate, Collaborate Engage (ACCE).† WIVA promotes a collaborative, student-centered approach to ​developing young adults who are ready for college or a career. With the school’s individualized program, K-5 students learn at their own pace in a mastery-based curriculum. Middle school students study core subjects as well as self-guided electives in music or world language. High schoolers have a diversity of options for meeting their educational needs. This full-time, tuition-free, online public charter school is authorized by the McFarland School District. Monroe Virtual Middle School​​ The Monroe Virtual Middle School (MVMS) uses computer-based courses, correspondence, independent study and experiential credit-based options to offer a flexible approach to earning middle school credit. Approved by the School District of Monroe Board of Education, MVMS offers a three-year middle school diploma. The MVMS program understands that all students are entitled to have the opportunity to earn a middle school education, but not all students are well served in a traditional classroom setting.  Students at MVMS can earn credit for work study and service learning.​ eAchieve Academy The vision of the eAchieve Academy team  is as follows: â€Å"Using todays technology to educate tomorrows leaders.†Ã‚  All Academy faculty and staff pledge to help students develop to their full potential and lay the groundwork for life success. To bolster that pledge, the curriculum at eAchieve is constantly evolving, as courses, technologies and social opportunities are added to address the needs of the diverse student body. First known as iQAcademy Wisconsin, eAchieve Academy has the most graduates and some of the best ACT and high school WKCE scores of any online Wisconsin high school. eAchieve added its virtual middle school in 2009 and its virtual elementary school in 2014. The school can boast of four National Merit Scholar Finalists and 916 total high school graduates since 2004 (as of May 2017).